More marine natural products have been derived from sponges than any other invertebrate phylum. Research on compounds with potential therapeutic application often requires a greater amount than can be supplied by collection or synthesis. The long-term objective of the proposed research is to develop invertebrate cell culture methods as an alternative to large-scale collections of marine invertebrates for bulk production of potential therapeutic agents derived from marine natural products. The specific aims are to develop methods for cell culture of selected species of bioactive marine sponges and the production of bioactive metabolites in culture. The emphasis of the proposed research will be on establishing axenic cell cultures of at least two species of bioactive sponges (both from shallow and deep water), determining nutritional requirements of the cells in culture, and optimizing culture conditions for production of bioactive metabolites.